Hi Devcam,
Which part is getting hot inside?
I could not find schematics for this amp, just for the Alpine-3550:
https://elektrotanya.com/alpine_3550_schematic.pdf/download.htmlI am guessing that it is a similar amp with a different power rating.
You need to verify that!
Assuming it is similar, do check the power supply, from the PS filter cap voltage ratings it must be something like +/-25V - +/-28V.
The PS uses a TL494 type IC, you could debug the PS circuit based on the IC's datasheet.
The amps are "regular" linear audio amps, using ICs and discrete power transistors.
Lots of info out there on how to debug those.
Do verify if your amp matches this "generic scheme".
Let us know if this is the case, and any other questions you might have.
Regards, Peter